Rotary device for decorticating painted surfaces



Dem-2, 194i. w. A. DANFoRTH 2,254,278

ROTARY DEVICE FOR DECORTICATING PAINTED SURFACES Filed April 15, 1938 BY TTORNEYS;

Patented Dec. 2, 1.941

ROTARY DEVICE FOR DECORTICATING PAINTED ,"SURFACES Walter A. Danfdl'l'th, Bangor, Maine Application April 13, 1938, Serial No. 201,767

5 Claims.

My present invention relates to methods of and apparatus for removing paint from clapboarded buildings and like surfaces.

Since the quality of the repainting of a building is dependent in part on its preparation for a new coat or coats of paint, the problem of removing the old paint is one of fundamental importance and one on which cost and effectiveness of the repainting depend.

The problem of removing the old paint has been widely appreciated. While loose paint is commonly removed by casual scraping, this is, of course. a slow method and ineffective when the paint is in any other condition.

Because this method was so` obviously unsatisfactory, attempts were made to provide for the more rapid and more complete removal of the paint. The burning of the paint frombuildings has been attempted but its use is really a failure since unlessthe utmost precautionris used, the wood is so affected that after the building had been repainted defects would appear requiring extensive work to make the job satisfactory. This method was further objectionable because of the risk of re to the building or contents.

Removal of the paint by Sandblasting has also been attempted, but this method has likewise proved unsatisfactory on account of the free dust in the air and in that not only was it extremely expensive but the results were uneven and therefore objectionable apart `from the expense.

According to my concept I provide a Vrotary device preferably driven by a relatively high speed portable motor which may be readily carried by the workman. In accordance with my invention I maytremove simultaneously the paint from the surface of one clapboard and the butt end of the overlapping clapbcard.

Because the paint is frequently uneven, both in terms of thickness and in quality, I have provided that the depth of operation may be accurately controlled by the operator. This may be effected byv providing a support for the device which at all times remains in contact with the surface and permits the depths of cutting to be rapidly to remove the paint or like surface coatings from a clapboarded or otherwise surfaced building, permitting greater economy in painting buildings through a reduction in cost of the work, and a longer period of attractive appearance, as

In the drawing I have indicated a tool or scraping device according to my invention by which my novel method of operation and use will be readily apparent to those skilled in the art. drawing: Y

Fig. 1 is a perspective view of a rotary scraping device with a portable motor and sling for carrying, in accordance with my invention.

Fig. 2 is a side view of such a device indicated as used in the practice of operation according to my method, and

Fig. 3 shows a side view of the device in position to cut simultaneously the paint from 'a clap- `board surface and the butt of the clapboard or board next above" and partly broken away to expose its interior. x l Aspart of Fig. 1 I have shown a motor M mounted on a support I and adapted to be carried by the operator by means of the shoulder sling 2. Current is supplied to the motor M from any suitable source (not shown) by a wire or cord 3 of convenient length.

The device'shown includes side members 4 and 5, tapered at one end. The side member 6 adjacent its tapered end has a hub 6 to receive the end of the flexible shafting 1 from the motor M which rotates the shaft 8, one end of which is supported in the bearing 9 carried by; the opposite side member di The cylindrical rotor I0 is preferably detachably held to the shaft 8 slotted as indicated at II in Fig. 3, which is shown as broken away to expose the key H2 and the slot H1 in the rotor with which it is engaged.

The sides 4 and 5 are apertured to receive the bolts I2 and lil fitted with nuts i21 and |61, respectively, and which when tightened up draw the sides toward each other. The bolt I6 passes through an aperture in the handle i3 which is thus detachably clamped at one end (of the frame of the tools. I thus provide for ready detachability when it is desired yto disassemble the device for cleaning or rotor replacement.VV

A cylindric guard i5 of slightly less than a semi-circular. arc in cross section is disposed partially about the rotor l0. 'I'his guard l5 is provided with pins I1 at botli ends to adjustably engage either of two `or more sets of holes I6 in the side members 4 and 5.

The sets of holes I6 are spaced at different distances from the axis of the shaft so as to provide for clearance where different sizes of rotors are used, or where more clearance is desired forl any otherfpurpose. I have only shown two sets well as useful protection of the building surface. 55 of pin holes I6 but obviously any number of sets :inthel of holes may be used and'disposed'in any manner desired. By making an odd number of pins and concentric holes the guard may be circumferentially adjusted. Obviously other holding or adjusting means equivalent in function to the pins and holes indicated as preferred in the particular scraper I have shown for the purposes of illustrating my invention, may be substituted.

'I'he side members 4 and 5i are braced and spaced by the guard I5 which is clamped rigidly in place by the bolts 2 and It. The bolt I2 is disposed as close to the rotor I as is consistent with the adjustments of the guard I and thus occupies a position of advantage in bracing and trussing the tool against the vibrations of its rapidly spinning rotor I|r-when at work. The

" edges |51 of the guard are rounded to make it in cylinder, preferably Vof steel, having an axial bore for` the shaft 8. The rotor I0 is provided with a plurality of longitudinally disposed edges 2|. The edges 2| are disposed forwardly or in the intended direction of` rotation while the rotor surface adjacent is sloped backward t0 channel-like fiutings 22 which give clearance for the paint as it is scraped or scavenged from the surface of a clapb'oard or the like, as at C (Fig. 3).

These scrapings are sometimes stringy or ribbon-like where the paint was too oily, or the paint surface P applied in wet weather, or was otherwise rubbery or sticky, as by not having dried out properly, or the paint may be removed as flakes or dust, as by decorticative action at `high speed. The edges 2| spaced along the pe` riplfery, line up with radial edges 23 with channels 215 between them, as best seen in Fig. 2.l

In use the operator moves the device along the elapboard C, ordinarily traversing it from right to left, as viewed in Fig. 2, with one edge of the support I5 in contact with'the worksurface. When properly positioned one end of the rotor I0 may bear against the butt end of the clapboard or like overhanging surface part or any projection C next above a vertically disposed work surface, so that as the device is drawn along, the paint P is removed from the overhanging butt edge of one clapboard by the end edges 23 while at the same time the longitudinal edges 2| are decorticating the exposed surface next below it. The motor is preferably of high speed, for example 3000 R. P. M. so that the longitudinally disposed edges 2| are spun rapidly against the paint surface P and so take oif the old paint smoothly and quickly.

In use the tool is held by its handle I3 with the The guard I5 is cut away on both sides at its end opposite the connection of the flexible drive shafting 1. sion I52 the end surface of which, carrying the pins I'I, contacts the inner face of the side member 4. More importantly it provides, laterally of the extension |52, ports 25 to give clearance immediately adjacent the end edges 23 and allow paint scrapings to escape and not be pocketed at the end of the combined guard and guide l5.

While my invention is particularly adapted to the removal of paint from a building, it will be appreciated thai; the rotary member ill may be easily replaced by any cylindrical rotor tool desired for any class of work so that my device may be utilized as a tool for many purposes.

What I therefore claim and desire to secure by Letters Patent is: 1. A device for use in preparing a coated surface for refinishing, said device comprising a pair of side frames,.a decorticating member rotatably supported by said side frames, means to rotateV said member, and means engageable by the operator to permit said device to be held in operative positions on said surfaces, said last named means comprising a handle carried by said side frames, a guard carried by saidv frame, means to support said guard in any one of a plurality of positions relativeto the axis of rotation .of said member intermediate said handle and said contacting decorticating member, and means to clamp said side frames together to hold said member, said guard and said handle in position,

said guard including a surface contacting portion operators fingers bearing against the upper por work, and therefore effect by touch the depth of cutting of the rotor I0. Usually the tool is traversed over the work bythe operator from right to left, as suggested in Fig. 2 as the depth of cutting cannot be as accurately controlled if `the tool be traversed in the opposite direction.

establishing `a slidable support for said device rearwardly of said vdecorticating member and a portion extending forwardly of said surface contacting portion, to permit engaging pressures to be distri-buted relative to said surface contacting portion to control the depth of attack of said member.

2. A device for use in preparing a coated surface for refinishing, said device comprising a pair` d of side frames, a decorticating member rotatably supported by said side frames, means to rotate said member, and means engageable by the oner hand of the operator to permit said device to be held in operative positions on said surface, said last named means comprising a handle carried by said side frames, a guard carried'by said frames intermediate said handle and said decorticating member, said guard including a surface contacting portion establishing a slidable support for said device rearwardly of said decorticating member and a portion extending forwardlylof said surface' contacting portion and being engageable by the fingers of the hand of the user in engagement with said handle to permit engaging pressures to be distributed relative to said surface contacting portion to control the depth of attack of said decorticating member.

3. The device of claim 2, the guard being a substantially semi-cylindrical shell mounted at either end in rsaid side frames and of slightly larger diameter than the radius of the decorticating member.

4. The device of 4claim 2, the guard being a substantially semi-cylindrical shell mounted at either end of said side frames and of slightly larger diameter than the radius of the decorticating member, portions of the ends of said shell being removed to permit the escape of matter from the space between said shell and the decorticating member.

5. A device for use in preparing a coated sur- This leaves a shortarcuate extenface` for renishing, said device comprising a f portion, and 'a portion over said decorticatingV member spaced from said handle portion for engagement by the iingers of the hand in engagement with said handle, said surface contacting `portion being intermediate said two last named portions and constituting a. fulcrum for said device, the depth of attack of said decorticating member being controlled by pressure applied to said portion over said decorticating member.

`WA'L'IlizR. A. DANFORTH. 

